Erosion Control BMPs Flashcards
7 cards from real CESSWI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Erosion Control BMPs flashcards as text
An inspector observes that fiber rolls installed on a slope have gaps larger than 1 inch between the roll and the soil surface. What problem does this create?
Answer: Runoff bypasses the roll by flowing underneath rather than being slowed
Gaps beneath fiber rolls allow runoff to channel under the device, bypassing its flow-retarding function entirely.
Which of the following is a key advantage of biodegradable erosion control blankets over plastic netting blankets?
Answer: They do not need to be removed and will not entangle wildlife
Biodegradable blankets decompose naturally, eliminating wildlife entanglement hazards and the labor cost of removal after vegetation establishes.
A temporary seeding BMP specifies using annual ryegrass. What is the PRIMARY purpose of annual ryegrass in this application?
Answer: Rapid germination and cover to protect soil until permanent species establish
Annual ryegrass germinates quickly, providing fast interim ground cover to protect disturbed soil until slower-establishing permanent species take hold.
What is the recommended maximum ponding depth behind a rock check dam in a drainage swale?
Answer: 1.5 feet
Rock check dams are typically designed to limit ponding to approximately 1.5 feet to prevent overtopping damage and upstream saturation.
During a post-storm inspection, an inspector finds that a silt fence has been undermined by concentrated flow. What does this indicate about the original BMP design?
Answer: The silt fence was placed in a concentrated flow path where it should not have been used
Silt fences are designed for sheet flow only; placement in concentrated flow areas is a fundamental design error that leads to failure.
Which erosion control BMP is MOST appropriate for protecting a freshly graded cut slope in a semi-arid climate where irrigation is not available?
Answer: Bonded fiber matrix (BFM) hydraulic mulch
BFMs create a continuous bonded matrix that protects soil and retains moisture to support seed germination even in dry conditions without irrigation.
According to SWPPP requirements, how soon after rain events must a CESSWI-level inspection of erosion controls be conducted?
Answer: Within 24 hours after a 0.25-inch or greater rain event
Most Construction General Permits require inspection within 24 hours following a qualifying storm event (typically ≥0.25 inch) to assess BMP performance.